Golden GAC 200 is a hard, acrylic extender for non-porous surfaces like glass. As the hardest and least flexible of Golden Acrylic Mediums, it is a liquid acrylic polymer emulsion that is useful for increasing film hardness and reducing tack. Used in its pure form, it is limited to applications on non-flexible supports. The amount of GAC 200 used should not exceed 33% of the entire paint mixture. Contains 8 oz.